Breast cancer can be detected five years before the onset of clinical signs in patients thanks to a blood test that can identify the body's immune responses to tumor cells. That's the statement that was made about the research that will be presented at a national cancer conference in Glasgow on Sunday. However, other cancer experts have warned that these claims should be treated with caution.
The study is the work of researchers at the School of Medicine at the University of Nottingham who focus on chemicals known as antigens. They are produced by cancer cells and elicit an immune response in humans. In particular, they cause our bodies to produce auto-antibodies that target and try to block these invading antigens.
Researchers want to know if they can detect the presence of specific auto-antibodies in patients and show whether they have been triggered by tumor cell antigens. The team thus took blood samples from 90 patients recently diagnosed with breast cancer. They compared them with samples taken from a control group of 90 patients without breast cancer.
Finally, the group examined the blood samples to see if they could detect auto-antibodies induced by tumor antigens. Researchers correctly identified breast cancer in 37% of the blood samples taken from affected patients. Crucially, they were also able to show that there was no cancer in 79% of the controls.
The results are considered highly encouraging by the group, which they say indicates that it will be possible to detect early breast cancer in this way.
"The results of our study show that breast cancer causes auto-antibodies against specific tumor associated antigens," says Denmark Alfatani, one of Nottingham's team. "We were able to detect the cancer with reasonable accuracy by identifying these auto-antibodies in the blood. After improving the accuracy of the test, it then opens the possibility of using a simple blood test to improve early detection of the disease, "adds Alfatani, who will present the study at the annual conference of the National Cancer Research Institute.
"We have found that these tumor associated antigens are good indicators of cancer. However, we need to develop and further validate this test. ”
Other researchers have urged caution in interpreting these results. "These are obviously very preliminary data," says Professor Paul Faroa of the University of Cambridge. "Much more research will be needed before any claim can be made that this is likely to be a significant advance in the early detection of cancer."
Molecular Oncologist at Warwick University Professor Lawrence Young agreed: "Although it is encouraging study, it is too early to state that this test can be used for screening for early breast cancer. More work is needed to increase the efficiency and sensitivity of cancer detection. "
The Nottingham team is now testing samples from 800 patients and expects the accuracy of the test to improve with these higher numbers.
'A blood test for early detection of breast cancer would be cost-effective, which would be of particular benefit in low- and middle-income countries. It would also be an easier screening method to use than current screening methods, such as mammograms, "says Alfatani.
Researchers believe that with a fully funded development program, the test can become available in the clinic in about four to five years.
The group is working on similar tests for pancreatic, colorectal and liver cancer. Solid tumors such as these, as well as lung and breast cancer, account for about 70% of all cancers.
In addition, a similar lung cancer test was tested in a randomized controlled trial in Scotland involving 12,000 people at highest risk for developing lung cancer because they smoke. Participants who test positive for auto-antibodies have a CT scan every two years to detect lung cancer in its early stages, when it is easier to treat.
"A blood test capable of detecting any of these cancers at an early stage is the predominant goal of our work," says Alfatani.